2 * Host Side support for RNDIS Networking Links
3 * Copyright (C) 2005 by David Brownell
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/netdevice.h>
22 #include <linux/etherdevice.h>
23 #include <linux/ethtool.h>
24 #include <linux/workqueue.h>
25 #include <linux/mii.h>
26 #include <linux/usb.h>
27 #include <linux/usb/cdc.h>
28 #include <linux/usb/usbnet.h>
29 #include <linux/usb/rndis_host.h>
33 * RNDIS is NDIS remoted over USB. It's a MSFT variant of CDC ACM ... of
34 * course ACM was intended for modems, not Ethernet links! USB's standard
35 * for Ethernet links is "CDC Ethernet", which is significantly simpler.
37 * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete. Issues
39 * - Power management in particular relies on information that's scattered
40 * through other documentation, and which is incomplete or incorrect even
42 * - There are various undocumented protocol requirements, such as the
43 * need to send unused garbage in control-OUT messages.
44 * - In some cases, MS-Windows will emit undocumented requests; this
45 * matters more to peripheral implementations than host ones.
47 * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
49 * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
50 * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
51 * currently rare) "Ethernet Emulation Model" (EEM).
55 * RNDIS notifications from device: command completion; "reverse"
58 void rndis_status(struct usbnet *dev, struct urb *urb)
60 netdev_dbg(dev->net, "rndis status urb, len %d stat %d\n",
61 urb->actual_length, urb->status);
62 // FIXME for keepalives, respond immediately (asynchronously)
63 // if not an RNDIS status, do like cdc_status(dev,urb) does
65 EXPORT_SYMBOL_GPL(rndis_status);
68 * RNDIS indicate messages.
70 static void rndis_msg_indicate(struct usbnet *dev, struct rndis_indicate *msg,
73 struct cdc_state *info = (void *)&dev->data;
74 struct device *udev = &info->control->dev;
76 if (dev->driver_info->indication) {
77 dev->driver_info->indication(dev, msg, buflen);
79 switch (msg->status) {
80 case RNDIS_STATUS_MEDIA_CONNECT:
81 dev_info(udev, "rndis media connect\n");
83 case RNDIS_STATUS_MEDIA_DISCONNECT:
84 dev_info(udev, "rndis media disconnect\n");
87 dev_info(udev, "rndis indication: 0x%08x\n",
88 le32_to_cpu(msg->status));
94 * RPC done RNDIS-style. Caller guarantees:
95 * - message is properly byteswapped
96 * - there's no other request pending
97 * - buf can hold up to 1KB response (required by RNDIS spec)
98 * On return, the first few entries are already byteswapped.
100 * Call context is likely probe(), before interface name is known,
101 * which is why we won't try to use it in the diagnostics.
103 int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf, int buflen)
105 struct cdc_state *info = (void *) &dev->data;
110 u32 xid = 0, msg_len, request_id;
112 /* REVISIT when this gets called from contexts other than probe() or
113 * disconnect(): either serialize, or dispatch responses on xid
116 /* Issue the request; xid is unique, don't bother byteswapping it */
117 if (likely(buf->msg_type != RNDIS_MSG_HALT &&
118 buf->msg_type != RNDIS_MSG_RESET)) {
122 buf->request_id = (__force __le32) xid;
124 master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
125 retval = usb_control_msg(dev->udev,
126 usb_sndctrlpipe(dev->udev, 0),
127 USB_CDC_SEND_ENCAPSULATED_COMMAND,
128 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
130 buf, le32_to_cpu(buf->msg_len),
131 RNDIS_CONTROL_TIMEOUT_MS);
132 if (unlikely(retval < 0 || xid == 0))
135 // FIXME Seems like some devices discard responses when
136 // we time out and cancel our "get response" requests...
137 // so, this is fragile. Probably need to poll for status.
139 /* ignore status endpoint, just poll the control channel;
140 * the request probably completed immediately
142 rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
143 for (count = 0; count < 10; count++) {
144 memset(buf, 0, CONTROL_BUFFER_SIZE);
145 retval = usb_control_msg(dev->udev,
146 usb_rcvctrlpipe(dev->udev, 0),
147 USB_CDC_GET_ENCAPSULATED_RESPONSE,
148 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
151 RNDIS_CONTROL_TIMEOUT_MS);
152 if (likely(retval >= 8)) {
153 msg_len = le32_to_cpu(buf->msg_len);
154 request_id = (__force u32) buf->request_id;
155 if (likely(buf->msg_type == rsp)) {
156 if (likely(request_id == xid)) {
157 if (unlikely(rsp == RNDIS_MSG_RESET_C))
159 if (likely(RNDIS_STATUS_SUCCESS
162 dev_dbg(&info->control->dev,
163 "rndis reply status %08x\n",
164 le32_to_cpu(buf->status));
167 dev_dbg(&info->control->dev,
168 "rndis reply id %d expected %d\n",
170 /* then likely retry */
171 } else switch (buf->msg_type) {
172 case RNDIS_MSG_INDICATE: /* fault/event */
173 rndis_msg_indicate(dev, (void *)buf, buflen);
176 case RNDIS_MSG_KEEPALIVE: { /* ping */
177 struct rndis_keepalive_c *msg = (void *)buf;
179 msg->msg_type = RNDIS_MSG_KEEPALIVE_C;
180 msg->msg_len = cpu_to_le32(sizeof *msg);
181 msg->status = RNDIS_STATUS_SUCCESS;
182 retval = usb_control_msg(dev->udev,
183 usb_sndctrlpipe(dev->udev, 0),
184 USB_CDC_SEND_ENCAPSULATED_COMMAND,
185 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
188 RNDIS_CONTROL_TIMEOUT_MS);
189 if (unlikely(retval < 0))
190 dev_dbg(&info->control->dev,
191 "rndis keepalive err %d\n",
196 dev_dbg(&info->control->dev,
197 "unexpected rndis msg %08x len %d\n",
198 le32_to_cpu(buf->msg_type), msg_len);
201 /* device probably issued a protocol stall; ignore */
202 dev_dbg(&info->control->dev,
203 "rndis response error, code %d\n", retval);
207 dev_dbg(&info->control->dev, "rndis response timeout\n");
210 EXPORT_SYMBOL_GPL(rndis_command);
215 * Performs a query for @oid along with 0 or more bytes of payload as
216 * specified by @in_len. If @reply_len is not set to -1 then the reply
217 * length is checked against this value, resulting in an error if it
220 * NOTE: Adding a payload exactly or greater than the size of the expected
221 * response payload is an evident requirement MSFT added for ActiveSync.
223 * The only exception is for OIDs that return a variably sized response,
224 * in which case no payload should be added. This undocumented (and
225 * nonsensical!) issue was found by sniffing protocol requests from the
226 * ActiveSync 4.1 Windows driver.
228 static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
229 void *buf, __le32 oid, u32 in_len,
230 void **reply, int *reply_len)
235 struct rndis_msg_hdr *header;
236 struct rndis_query *get;
237 struct rndis_query_c *get_c;
243 memset(u.get, 0, sizeof *u.get + in_len);
244 u.get->msg_type = RNDIS_MSG_QUERY;
245 u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
247 u.get->len = cpu_to_le32(in_len);
248 u.get->offset = cpu_to_le32(20);
250 retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
251 if (unlikely(retval < 0)) {
252 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
257 off = le32_to_cpu(u.get_c->offset);
258 len = le32_to_cpu(u.get_c->len);
259 if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
262 if (*reply_len != -1 && len != *reply_len)
265 *reply = (unsigned char *) &u.get_c->request_id + off;
271 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
272 "invalid response - off %d len %d\n",
277 /* same as usbnet_netdev_ops but MTU change not allowed */
278 static const struct net_device_ops rndis_netdev_ops = {
279 .ndo_open = usbnet_open,
280 .ndo_stop = usbnet_stop,
281 .ndo_start_xmit = usbnet_start_xmit,
282 .ndo_tx_timeout = usbnet_tx_timeout,
283 .ndo_set_mac_address = eth_mac_addr,
284 .ndo_validate_addr = eth_validate_addr,
288 generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
291 struct net_device *net = dev->net;
292 struct cdc_state *info = (void *) &dev->data;
295 struct rndis_msg_hdr *header;
296 struct rndis_init *init;
297 struct rndis_init_c *init_c;
298 struct rndis_query *get;
299 struct rndis_query_c *get_c;
300 struct rndis_set *set;
301 struct rndis_set_c *set_c;
302 struct rndis_halt *halt;
305 __le32 phym_unspec, *phym;
309 /* we can't rely on i/o from stack working, or stack allocation */
310 u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
313 retval = usbnet_generic_cdc_bind(dev, intf);
317 u.init->msg_type = RNDIS_MSG_INIT;
318 u.init->msg_len = cpu_to_le32(sizeof *u.init);
319 u.init->major_version = cpu_to_le32(1);
320 u.init->minor_version = cpu_to_le32(0);
322 /* max transfer (in spec) is 0x4000 at full speed, but for
323 * TX we'll stick to one Ethernet packet plus RNDIS framing.
324 * For RX we handle drivers that zero-pad to end-of-packet.
325 * Don't let userspace change these settings.
327 * NOTE: there still seems to be wierdness here, as if we need
328 * to do some more things to make sure WinCE targets accept this.
329 * They default to jumbograms of 8KB or 16KB, which is absurd
330 * for such low data rates and which is also more than Linux
331 * can usually expect to allocate for SKB data...
333 net->hard_header_len += sizeof (struct rndis_data_hdr);
334 dev->hard_mtu = net->mtu + net->hard_header_len;
336 dev->maxpacket = usb_maxpacket(dev->udev, dev->out, 1);
337 if (dev->maxpacket == 0) {
338 netif_dbg(dev, probe, dev->net,
339 "dev->maxpacket can't be 0\n");
341 goto fail_and_release;
344 dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
345 dev->rx_urb_size &= ~(dev->maxpacket - 1);
346 u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
348 net->netdev_ops = &rndis_netdev_ops;
350 retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
351 if (unlikely(retval < 0)) {
352 /* it might not even be an RNDIS device!! */
353 dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
354 goto fail_and_release;
356 tmp = le32_to_cpu(u.init_c->max_transfer_size);
357 if (tmp < dev->hard_mtu) {
358 if (tmp <= net->hard_header_len) {
360 "dev can't take %u byte packets (max %u)\n",
363 goto halt_fail_and_release;
366 "dev can't take %u byte packets (max %u), "
367 "adjusting MTU to %u\n",
368 dev->hard_mtu, tmp, tmp - net->hard_header_len);
370 net->mtu = dev->hard_mtu - net->hard_header_len;
373 /* REVISIT: peripheral "alignment" request is ignored ... */
375 "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
376 dev->hard_mtu, tmp, dev->rx_urb_size,
377 1 << le32_to_cpu(u.init_c->packet_alignment));
379 /* module has some device initialization code needs to be done right
380 * after RNDIS_INIT */
381 if (dev->driver_info->early_init &&
382 dev->driver_info->early_init(dev) != 0)
383 goto halt_fail_and_release;
385 /* Check physical medium */
387 reply_len = sizeof *phym;
388 retval = rndis_query(dev, intf, u.buf, OID_GEN_PHYSICAL_MEDIUM,
389 0, (void **) &phym, &reply_len);
390 if (retval != 0 || !phym) {
391 /* OID is optional so don't fail here. */
392 phym_unspec = RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED;
395 if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
396 *phym != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
397 netif_dbg(dev, probe, dev->net,
398 "driver requires wireless physical medium, but device is not\n");
400 goto halt_fail_and_release;
402 if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
403 *phym == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
404 netif_dbg(dev, probe, dev->net,
405 "driver requires non-wireless physical medium, but device is wireless.\n");
407 goto halt_fail_and_release;
410 /* Get designated host ethernet address */
411 reply_len = ETH_ALEN;
412 retval = rndis_query(dev, intf, u.buf, OID_802_3_PERMANENT_ADDRESS,
413 48, (void **) &bp, &reply_len);
414 if (unlikely(retval< 0)) {
415 dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
416 goto halt_fail_and_release;
418 memcpy(net->dev_addr, bp, ETH_ALEN);
419 memcpy(net->perm_addr, bp, ETH_ALEN);
421 /* set a nonzero filter to enable data transfers */
422 memset(u.set, 0, sizeof *u.set);
423 u.set->msg_type = RNDIS_MSG_SET;
424 u.set->msg_len = cpu_to_le32(4 + sizeof *u.set);
425 u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
426 u.set->len = cpu_to_le32(4);
427 u.set->offset = cpu_to_le32((sizeof *u.set) - 8);
428 *(__le32 *)(u.buf + sizeof *u.set) = RNDIS_DEFAULT_FILTER;
430 retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
431 if (unlikely(retval < 0)) {
432 dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
433 goto halt_fail_and_release;
441 halt_fail_and_release:
442 memset(u.halt, 0, sizeof *u.halt);
443 u.halt->msg_type = RNDIS_MSG_HALT;
444 u.halt->msg_len = cpu_to_le32(sizeof *u.halt);
445 (void) rndis_command(dev, (void *)u.halt, CONTROL_BUFFER_SIZE);
447 usb_set_intfdata(info->data, NULL);
448 usb_driver_release_interface(driver_of(intf), info->data);
454 EXPORT_SYMBOL_GPL(generic_rndis_bind);
456 static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
458 return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
461 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
463 struct rndis_halt *halt;
465 /* try to clear any rndis state/activity (no i/o from stack!) */
466 halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
468 halt->msg_type = RNDIS_MSG_HALT;
469 halt->msg_len = cpu_to_le32(sizeof *halt);
470 (void) rndis_command(dev, (void *)halt, CONTROL_BUFFER_SIZE);
474 usbnet_cdc_unbind(dev, intf);
476 EXPORT_SYMBOL_GPL(rndis_unbind);
479 * DATA -- host must not write zlps
481 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
483 /* peripheral may have batched packets to us... */
484 while (likely(skb->len)) {
485 struct rndis_data_hdr *hdr = (void *)skb->data;
486 struct sk_buff *skb2;
487 u32 msg_len, data_offset, data_len;
489 msg_len = le32_to_cpu(hdr->msg_len);
490 data_offset = le32_to_cpu(hdr->data_offset);
491 data_len = le32_to_cpu(hdr->data_len);
493 /* don't choke if we see oob, per-packet data, etc */
494 if (unlikely(hdr->msg_type != RNDIS_MSG_PACKET ||
495 skb->len < msg_len ||
496 (data_offset + data_len + 8) > msg_len)) {
497 dev->net->stats.rx_frame_errors++;
498 netdev_dbg(dev->net, "bad rndis message %d/%d/%d/%d, len %d\n",
499 le32_to_cpu(hdr->msg_type),
500 msg_len, data_offset, data_len, skb->len);
503 skb_pull(skb, 8 + data_offset);
505 /* at most one packet left? */
506 if (likely((data_len - skb->len) <= sizeof *hdr)) {
507 skb_trim(skb, data_len);
511 /* try to return all the packets in the batch */
512 skb2 = skb_clone(skb, GFP_ATOMIC);
515 skb_pull(skb, msg_len - sizeof *hdr);
516 skb_trim(skb2, data_len);
517 usbnet_skb_return(dev, skb2);
520 /* caller will usbnet_skb_return the remaining packet */
523 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
526 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
528 struct rndis_data_hdr *hdr;
529 struct sk_buff *skb2;
530 unsigned len = skb->len;
532 if (likely(!skb_cloned(skb))) {
533 int room = skb_headroom(skb);
535 /* enough head room as-is? */
536 if (unlikely((sizeof *hdr) <= room))
539 /* enough room, but needs to be readjusted? */
540 room += skb_tailroom(skb);
541 if (likely((sizeof *hdr) <= room)) {
542 skb->data = memmove(skb->head + sizeof *hdr,
544 skb_set_tail_pointer(skb, len);
549 /* create a new skb, with the correct size (and tailpad) */
550 skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
551 dev_kfree_skb_any(skb);
556 /* fill out the RNDIS header. we won't bother trying to batch
557 * packets; Linux minimizes wasted bandwidth through tx queues.
560 hdr = (void *) __skb_push(skb, sizeof *hdr);
561 memset(hdr, 0, sizeof *hdr);
562 hdr->msg_type = RNDIS_MSG_PACKET;
563 hdr->msg_len = cpu_to_le32(skb->len);
564 hdr->data_offset = cpu_to_le32(sizeof(*hdr) - 8);
565 hdr->data_len = cpu_to_le32(len);
567 /* FIXME make the last packet always be short ... */
570 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
573 static const struct driver_info rndis_info = {
574 .description = "RNDIS device",
575 .flags = FLAG_ETHER | FLAG_FRAMING_RN | FLAG_NO_SETINT,
577 .unbind = rndis_unbind,
578 .status = rndis_status,
579 .rx_fixup = rndis_rx_fixup,
580 .tx_fixup = rndis_tx_fixup,
583 /*-------------------------------------------------------------------------*/
585 static const struct usb_device_id products [] = {
587 /* RNDIS is MSFT's un-official variant of CDC ACM */
588 USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
589 .driver_info = (unsigned long) &rndis_info,
591 /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
592 USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
593 .driver_info = (unsigned long) &rndis_info,
595 /* RNDIS for tethering */
596 USB_INTERFACE_INFO(USB_CLASS_WIRELESS_CONTROLLER, 1, 3),
597 .driver_info = (unsigned long) &rndis_info,
601 MODULE_DEVICE_TABLE(usb, products);
603 static struct usb_driver rndis_driver = {
604 .name = "rndis_host",
605 .id_table = products,
606 .probe = usbnet_probe,
607 .disconnect = usbnet_disconnect,
608 .suspend = usbnet_suspend,
609 .resume = usbnet_resume,
612 static int __init rndis_init(void)
614 return usb_register(&rndis_driver);
616 module_init(rndis_init);
618 static void __exit rndis_exit(void)
620 usb_deregister(&rndis_driver);
622 module_exit(rndis_exit);
624 MODULE_AUTHOR("David Brownell");
625 MODULE_DESCRIPTION("USB Host side RNDIS driver");
626 MODULE_LICENSE("GPL");